Improvement in backlash-springs



UNITED STATES PATENT OFFICE.

THOMAS ALSOP, OF ELKHART CITY, ILLINOIS.

IMPROVEMENT IN BACKLASH-SPRINGS.

Specification forming part of Letters Patent No. 172,366, dated January18, 1876; application filed January 3, 1876.

To all whomt't may concern:

Be it known that I, THOMAS ALSOP, of Elkhart, in the county of Logan andState of Illinois, have invented a new and Improved Backlash-Spring, ofwhich the following is a specification:

In the accompanying drawing, Figure 1 represents a side elevation of myimproved backlash-spring, partly in section, on line 0 0, Fig.2, asapplied to a shaft and pinion; and Figs. 2 and 3 are vertical transversesections of the same, respectively, on the lines as w and y y, Fig. 1.

Similar letters of reference indicate corresponding parts.

The invention relates to an improved backlashspring for mill spindles,shaftings, 850., which bears equally on the pinion at both sides of theshaft, and takes up the backlash uniformly' throughout the whole lengthof the spring, producing a more durable spring, as friction is obviatedand no tensile strain ex erted thereon.

The invention consists, mainly, of one or more springs, coupled togetherand applied at one end by a fixed sleeve or clutch to the shaft, and atthe other end to a loose disk that engages by stops or pins the pinionthat transmits the power to intermeshing gearing.

In the drawing, A represents a mill spindle, shaft, or other device, towhich springs are to be applied for protecting the power-transmittinggearing against the injurious effects of backlash.Thetransmitting-pinion B is placed loosely 011 the shaft or spindle A,and acted upon by a loose disk, 0, with lugs or studs a, that engagediametrically-opposite arms of the pinion B, and bear equally on bothsides of the same, avoiding thereby the uneven wear of the spindle andpinion heretofore occasioned by the connection of the coiledbacklash-spring on one side of the pinion merely. The loose disk 0 isprovided with a sleeveshaped clutch, C, that engages by a projecting camthe end of the spring D, which is Wound singlyor doubly around thespindle, and seated with the opposite end on a similar sleeve or clutch,E, that is fixed to the spindle by a tongue, I), projecting into alongitudinal groove, b, of the spindle, and prevented from slidingthereon by a cross-pin, d. In case more than one spring is desired to,be employed they may be coupled together by means of loose intermediatesleeves or clutches with cams at both ends that engage the ends of thesprings and transmit the strain evenly through all the springs to thefixed sleeve, so as to bring them all into action.

By the. use of several strong springs a heavy strain can be met, andstill sufficient motion be obtained. The breaking or smashing of theteeth of the power-trailsmitting gearing by backlash is, by the uniformaction ofthe spring or springs, avoided, and the springs rendereddurable, as no friction or tensile strains are exerted thereon.

Having thus described n'iyinvention, I claim as new and desire to secureby Letters Patentv The combination, with a spindle or shaft and apower-tran smittin g pinion placed loosely thereon, of one or more.backlash-springs applied to a terminal fixed cam-sleeve or clutch, andto acam-sleeve placed on the shaft and engaging by pins or studs thepinion at diametrically-opposite points, substantially in the manner andfor the purpose set forth.

THOMAS ALSOP. Witnesses:

WM. H. DAVIS, E. B. NICHOLSON.

